Quá trình sinh học đóng một vai trò quan trọng trong việc chuyển đổi, vận động trên bề mặt tiểu. Nền văn hóa làm giàu cho một số Như loài khoan dung, tích cực giảm As (V) As (III). Không có thay đổi Như sự biệt hóa xảy ra trong các điều khiển, do đó xác nhận (V) giảm sinh học trung gian, và quá trình trao đổi chất hoạt động là một điều kiện tiên quyết để giảm. Khi lãi suất giảm (V) tăng trưởng khác nhau và được ghi nhận trong điều kiện oxic để phụ oxic,. | Natural Arsenic in Groundwater Occurrence Remediation and Management -Bundschuh Bhattacharya and Chandrasekharam eds 2005 Taylor Francis Group London ISBN 04 1536 700 X Microbial processes and arsenic mobilization in mine tailings and shallow aquifers J. Routh Department of Geology and Geochemistry Stockholm University Stockholm Sweden A. Saraswathy Department of Biology West Virginia State College West Virginia USA ABSTRACT Microbial processes play an important role in transforming and mobilizing As in the sub-surface. Enrichment cultures indicated several As tolerant species which actively reduced As V to As III . No change in As speciation occurred in the controls thereby confirming As V reduction was biologically mediated and active metabolism was a prerequisite for reduction. Different growth and As V reduction rates were noted under oxic to sub-oxic conditions and a zero-order model best fits the As V reduction data. Arsenic concentrations in the microcosms seem to affect biomass yield and As V reduction rates in some of the strains. Arsenic reduction in these microorganisms probably occurs for respiratory or detoxification purposes. It is likely that microbial mobilization of As may have an impact on groundwater remediation treatment in these environments. 1 INTRODUCTION Arsenic As compounds are highly toxic Nriagu 2002 . People have known about its lethal properties since antiquity and have often used arsenic trioxide As2O3 for homicide purposes. Renewed interest in the metalloid has increased dramatically but for different reasons. A recent paper by Bhattacharya et al. 2002 details the As crisis which affects the lives of general population en masse in several countries. The problem is nowhere as serious as it is in Bangladesh and India where more than 70 million people are at risk from drinking As-rich groundwater Harvey et al. 2003 . The first reports on clinical manifestation of As toxicity from this region came up around 1978 and thereafter chronic .
